Ok guys I'm too lazy to search for this answer... aproximately how much RWHP does 1 PSI of Boost equal ?

Background: I just discovered my Boost dump was hooked back up. I never noticed it because I went up in hp recently and all I could tell was that it felt stronger. Soooo... I seem to recall the dump lets of 3 PSI ?????

I'm trying to now figure out how much boost I have been losing and how much HP.... I should be pushing atleast 18psi with a bypass enabled.

BTW I guess I should mention I have every performance mod.

 

uhm, you weren't loosing any boost unless it opened, in which case you wouldn't have any and you would feel a huge difference. but i think 1lb is somewhere around 10hp very roughly

and oh yea bypass or not you dont gain any more boost

 

The truck only dumps boost on the shifts. It doesn't affect peak boost while in a gear. Unplugging the solenoid will de-activate the boost dump feature. You don't "gain" boost, per se, you just don't lose it.

I read on Troyerperformance.com that an additional 1psi of boost will yield around 6-8 HP. Gains depends greatly on temperature, how much boost you are already making, which blower, etc., etc. but it's a rule of thumb to go by.

 

Given a perfectly effecient engine, and a perfectly effecient blower that requires no HP to spin, 1psi=

YourHP at 0 boost=YH
Final HP=FH

FH=YH*((Boost+15)/15)

For real world numbers, search around for the excellent spreadsheet blowerrpm.xls this has real world data for our trucks.

And in your case, you weren't losing any HP anyway, so it doesn't really matter

Coldie

 

Disabling the boost dump will not add boost.

Regarding boost per PSIG, from my Web site:

"As a rough rule of thumb (extremely rough), a perfectly efficient 15 PSIG should double the HP of an engine (normal air pressure is about 15 PSI, so 30 total PSI=15 PSIG). Do the math and a perfectly efficient PSI should be worth about 6.6% gain.

Assume a 220 rwHP normally aspirated 5.4. Add a perfectly efficient 8 PSIG (theoretical 53% gain using the above rule of thumb). The expected rwHP should be about 335, which is about what one should expect from a stock Lightning. Add 4 more perfectly efficient PSIG (another theoretical 26%). That should yield 422 rwHP, which would be an 87 rwHP gain.

But it doesn't-- it only produces 15 rwHP. A perfectly efficient 6 PSIG pulley should yield 467 rwHP! But it doesn't--it only produces 18 rwHP, or a measly 3 rwHP gain for those extra two PSIG."

Note: the above refers only to peak rwHP -- there may be higher gains at lower or higher points on the scale.

Bottom line: The question of how much HP per PSIG cannot be answered unless a particular engine, supercharger, and RPM is known. Keep upping the RPMs on any supercharger and sooner or later you will not make any more HP, just heat.

 

On a Kenne Bell equipped Lightning adding 1 lb of boost is equal to 13.36 hp....supposedly....but who knows.

 

I guess I'll just dyno it this coming Saturday... she made 490/620 last time but that was on race fuel... I suspect the dump was re-activated because I took it to the track a week later and couldn't get better than 8.5 1/8th mile on slicks.... ugh.